Diagnostic Value of Metagenomic Next-Generation Sequencing for Pulmonary Infection in Intensive Care Unit and Non-Intensive Care Unit Patients.

Objective: To evaluate the diagnostic performance of metagenomic next-generation sequencing (mNGS) and culture in pathogen detection among intensive care unit (ICU) and non-ICU patients with suspected pulmonary infection. Methods: In this prospective study, sputum samples were collected from patients with suspected pulmonary infection for 2 consecutive days and then subjected to DNA or RNA sequencing by mNGS or culture; 62 ICU patients and 60 non-ICU patients were admitted. In the end, comparisons were made on the pathogen species identified by mNGS and culture, the overall performance of these two methods in pathogen detection, and the most common pathogens detected by mNGS between the ICU and non-ICU groups. Results: In DNA and RNA sequencing, the positive rate of pathogen detection reached 96.69% (117/121) and 96.43% (108/112), respectively. In culture tests, the positive rate of the pathogen was 39.34% (48/122), much lower than that of DNA and RNA sequencing. In general, the positive rate of pathogen detection by sputum mNGS was significantly higher than that of sputum culture in the total and non-ICU groups (p < 0.001) but did not show a significant difference when compared to the result of sputum culture in the ICU group (p = 0.08). Haemophilus spp., Candida albicans, Enterococcus spp., and viruses from the mNGS results were excluded before comparing the overall performance of these two methods in pathogen detection. Specifically, among the 10 most common bacteria implied from the mNGS results, significant differences were observed in the number of cases of Haemophilus parainfluenzae, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Staphylococcus aureus, and Enterococcus faecalis between the ICU and non-ICU groups (p < 0.05). Conclusions: This study demonstrated the superiority of mNGS over culture in detecting all kinds of pathogen species in sputum samples. These results indicate that mNGS may serve as a valuable tool to identify pathogens, especially for ICU patients who are more susceptible to mixed infections.

Improved Strength-Ductility of Ti-6Al-4V Casting Alloys with Trace Addition of TiC-TiB2 Nanoparticles.

In this work, a high strength-ductility Ti64 cast alloy, containing trace TiC-TiB2 nanoparticles, was fabricated by adding dual-phased nano-TiC-TiB2/Al master alloys to the molten Ti64 alloys. The trace addition of the TiC-TiB2 nanoparticles (0.1 wt%) simultaneously reduced the size of the ß grains, the α laths, and the α colony size of the lamellar structure during casting and suppressed the coarsening of the α laths during heat treatment. The yield strength and the uniform elongation of TiC-TiB2/Ti64 were increased by ~130 MPa and 2%, respectively. The simultaneously improved strength and ductility of the TiC-TiB2/Ti64 were attributed to the decrease in the α colony size of the lamellar structure, the significant refinement of the grains and α laths, and the pinning effect of nanoparticles.

An observational study of autologous bone marrow-derived stem cells transplantation in seven patients with nervous system diseases: a 2-year follow-up.

Currently, autologous bone marrow-derived stem cell is one of the most innovative areas of stem cells research. Previous studies on animal models of nervous system diseases have shown that these cells have a good effect on nervous system disorders. The alternative treatment with stem cells for the nervous system diseases has also gradually reached to clinical application stage. The prospect is captivating, but the safety and efficacy of this procedure need further research. To observe the clinical efficacy and side effects of the treatment for autologous mesenchymal stem cells and neural stem/progenitor cells which are in differentiated form by inducing with cerebrospinal fluid in the patients with nervous system diseases, thirty patients were selected from our hospital (2009-10 to 2012-07) and were followed at 1 month, 3 months, 6 months, 1 year and 2 years after the treatment with autologous mesenchymal stem cells and neural stem/progenitor cells in differentiated form was introduced. In this paper, we will introduce the process to make cells accessible for the clinical application by the description of the changes observed in 7 cases were followed for 2 years. The time for bone marrow mesenchymal stem cells could be available for clinical needs is as early as 5 days, not later than 10 days, and the median time is 8 days, while neural stem/progenitor cells in differentiated form can be available for clinical needs in as early as 12 days, not later than 15 days, and the median time is 13.5 days (statistical explanation: Case 5 only uses autologous mesenchymal stem cells, and Case 7 has two times bone marrow punctures). The neurological function of the patients was improved in 1-month follow-up, and the patients have a better discontinuous trend (statistical explanation: sometimes the neurological function of the patients between two adjacent follow-ups does not change significantly). After transplantation, four patients appeared to have transient fever, but it was easily controlled by symptomatic treatment. Seven patients did not appear to show secondary tumor induced by transplantation of stem cells in 2-year follow-up. Thus, it suggests that the use of autologous bone marrow-derived stem cells transplantation in patients with nervous system diseases is a feasible, convenient, safe, and effective method.